milk decrease

Casandra • 27 yrs old married for 10 years 😊we have two kids 9 and 8 and another on the way
I'm so sad 😔 my milk supply has decreased I don't know if it has anything to do with me having mastitis I kept feeding my baby and I'm talking antibiotics but my baby is not getting full and when I pump it barely comes out I don't know if it's a temporary thing 
Anyone have any advice? Thanks !